Separating apparatus



Dec. 23, 1958 B. 1. ZUBRZYCKI ETAL 2,865,504

SEPARATING APPARATUS 3 Sheets-Sheet 1 Filed Aug. 9, 1956 l VEN ORf I 55,52%? /12M%M %M 4 mm ATTORNEY Dec. 23, 1958 B. J. ZUBRZYCKI ET AL 2,

' SEPARATING APPARATUS Filed Aug. 9, 1956 3 Sheets-Sheet 2 I BY f AATTORNEYS a7 Dec. 23, 1958 B. J. ZUBRZYCKI ETAL 2,365,504

SEPARATING APPARATUS Filed Aug. 9, 1956 84 86 85 FIG. I0

840 850 A? FIG.

3 Sheets-Sheet 3 ATTORNEY;

United States Patent SEPARAIING ABPARAIUS B le l w hr ycld, Arvida, Qubeqand Ronal W lfred'laipesiewi s, Mp treal, Quebec, Canada, ass'ignorsto F. L. Smi dth & ,Co., New'Ybrk, N. Y., a corporation qwwe y j Ap afiwu ust 9, 9 6 s r a N 0 ,99

cg'niponents and a fine material, which can be earried' bit as acontinuous Qperatioh and at'little expense, and with apparatus; by whjehthe method can he Success fifllj practieed'. The tnetho d ahd apparatusof the in; tientiohhhay be employed in eOmreetiq-n with variousmanufacturing operatldns and offer special advantages, whenwgsed in the]treatment bf hot materialdischarged frtim akiln and ti; be ebbled in a cqol erpf the fluid bed typey g example pf s ich a'h'ot material iscalcined allirhinfir'n 'zjride', afhd 'the applicatid of the'methbq andapparatilst'o' the tr'eatmentbf 'that product will be illustrated anddeseribedf in 'qetaill fpr "purposes bf ekji lanatiqn.

" Th ma uf re of a m nu ox de is rd a i y q i g O y a c ni th 'rawma al.a" re ail! al'qng] a path bquhde'cl. adjaee t. thelpo'int of 'fveisalb'f fiQW by. ipdroiis Wall, th'rdti'gh v'vhie'hi'air is ir'ltr'c'xdfi'cedi t ojth '.m1 er to ffl uidize. it. The rate of supply. "of the aif'is"contf'olledfscb that the velocityv 'of the air decreases in a direetiodown. the wall but islow e'nou 'hfnea'ri the upper: end of the 'wall to,permit the f c r,e1g1i stthstanes'ahcl l'fimps' to sink and suflieiently2,865,504 .Rfleate P q- 23; 1. 58

2 its sjgqplest form, the apparatus. tor the practice 0f t me hpd n nd sa s pa ating ibe'r' havi l' t east one partjtieh ex tend'i g dbwriw afdfrphi the tgyva r dthe' chamber bbttdmfwhich ,is made bf at least 9 inne PO QI'JS w th q w h air Y qr' ne tion is introduced." The chamber"has ah in'letantl an outlet for material at ppppsite sides of the partiti citi and an outlet near the tower e d Of the inclined wall, thrsvs w ih e t d Q' i i i$ at; be removed. When the apparatus ls tc be hsedi qharld i ig. l nu 25d; di ha ed f m s1 a k'ilil a e d 1. a ui ed e e t saratist phamb'er may be bu iltin the. bottom of. leiln 1199a, sq thatthe material issfiihgfrpr'nf the kiln falls ihte the chamber at dhes'ide bf par t'i'tio fi: Thematerial. l t at he w ersteer t e fial ifin' mi l "t e lead glirectly into brie, fid Of the material passagethrohgh the'fltfi cl-lid camel: A

' Fer a better uiiderstanding of the invent'ipn, referencefmay be madethe aceqmpapyih g drawings, i i c Pig". 1 is a view, partly in yerticalseetion on the line l I bf"Fig.' 2 and partly in el e vat io n, of arotary ldht ihstallatiql ifi which asegarating'apparatus etnboelyi g they t' i 's lq e b t i e t e ki an a flair? it a s st ttl vi w 951 29t 1&29f P aa 4 e sect ws .9 3. 12. 9% 3 .3

high. jiiearthe "lower an of the alrtaimaimain' "the a s fz 5.;

flees! vi v a the term qt he s aratmg pparatusi rz er d eleyation.eitheapgaratus f Big and. I a.. 7: high. 9 1' 429 .ll te t t sasfistiqnal v ws: qt th modified forms o' p ra s t Fig. s,

. s l h s llai a.alhit a ssl 9 igs. 1 p9 4 5 8 1 2 t9? t e nra qtim qtal minum 192 2.1!. sunnqtteclfet si tts aak m at: an t the tiies the h aW s qss sk s settqm b a9 g tl-3 lfi?fi tram. and. $151-. ri a sof e a qe q b a battl tw sh. ri es w n. t e es. be 1 3 9 33. were?! 1 s at t ehQQh: Th if $11 F e is fq si ith aqct eninslead a h s i th m n spi 7 hut-fi -le d do. nd fr m the p The archiflextends without interruptionbetween the. frontand reatiwallsof thehood 25, but an opening is" formedin' arch 29. beneath the grate and between the barrier andtheirear vyallpf the housing. The materialfall ing thrbu gh the g'ra te acfcprdin'glydr'ops throiigh the ope ifig and e ters'a separating ehamhef 33 which isfbrmflbetwfi the W allsbfh eC d N w M 2w The a 1 3 1 convergefibso thateach pair' of chambers forms a trough.

at .91 was; the lines I e S 2 91 .959 t e-ls stti wviderlwith The lowerwall of each chamber is impervious, while the upper wall is porous, andair is supplied to the chambers through air supply pipes 36 havingvalves 37. The outer walls of the aerating chambers are formed toprovide a central outlet 38 at the bottom'of the separating chamber andthe outlet is normally closed by a removable door 38a. When air atsufiicient pressure is supplied to the chambers 34, 35, the air escapesthrough their porous inner walls and fiuidizes finely divided materialin the separating chamber.

A partition 39 extends downward from the junction of arches 29, 30 andterminates a distance above the air chambers 35. As soon as materialentering the separating chamber at one side of partition 39 through theopening through arch 29 becomes aerated, the material-flows beneath thelower end of the partition and rises on the other side of it. The risingmaterial is free to escape fromthe aerating chamber through a dischargeopening 40 in the rear wall of the hood 25. a

' The opening 40 leads into a fluid-bed cooler 41, which may be of'anyconventional type, and the cooler illustrated includes a housing 42, thefront wall of which is formed by the rear wall of hood 25. The housinghas an outlet in its rear wall in line with the inlet 40 and a partition44 subdivides the interior of the housing, so that the materialtraveling from the inlet 40 to the outlet 43 passes along one side ofthe partition and then returns along the other. The passages formaterial within the housing at opposite sides of the partition arefurther subdivided by partitions 45 attached to the housing walls and topartition 44 and arranged to cause the material traveling through thehousing on either side of the partition 44 to travel along a tortuouspath.

The pulverulent material traveling through the housing 42 is indirectlycooled by a cooling medium and, for this purpose, in the cooler shown,air pipes 46 of U-shape are mounted to lie horizontal and with theirends extending through wall 42a on opposite sides of the partition 44.Air is supplied to the inlet ends of the pipes through an inlet casing47 connected by a pipe 48 to the outlet of a fan, and the air issuingfrom pipes 46 enters an outlet casing 49 connected to a riser pipe 53.The pipe 53 is connected to an exhaust stack 54 and to a pipe 55, whichleads to an opening through the wall of hood 25. A damper 56 is mountedat the bottom of stack 54 and can be adjusted to determine the relativequantities of the air supplied to the hood to be used as secondary airof combustion in the kiln and allowed to escape up the stack. The bottomof the cooler is formed by aerating chambers 57 having porous upperwalls and supplied with air by pipes 58. p

In the use of the apparatus shown in Fig. 1 in the prm duction ofalumina, any large lumps of burned material issuing from the kiln passover the grating and, after entering the space 28 in the hood, aredischarged through the chute 32, while the material fine enough to passthrough the grate enters the separating chamber 33 at one through thecasing of the cooler along a tortuous path to pass around the end ofpartition 44 and return for discharge through opening 43. In its travelthrough the cooler, the material is cooled by indirect heat exchangewith air traveling through pipes 46 and part of the air thus heated isused as secondary air of combustion in the kiln while the remainder isdischarged.

In the installation of Fig. l, the separating chamber makes it possibleto eliminate from the finely divided aluminum oxide oversize components,which would fall out of the stream of material traveling through thefluidbed cooler and be deposited upon the aerating chambers at thebottom thereof. The deposit of such components upon the porous walls ofthe chambers would soonimpair the aerating action and reduce the coolerefiiciency and, if the components were not removed regularly, they mi htcause the cooler to clog. The separating chamber 33 between the kiln andthe cooler removes the undesired components from the finely dividedaluminum oxide, so that the cooling can proceed without interference. I

The essential features of a modified form of separating chamber 5%,which may be employed in place of chamber 33, are illustrated in Figs. 5to 7, inclusive, and the modified chamber is defined laterally by thewalls 25' of the kiln hood. The bottom of the separating chamber isformed by pairs of downwardly convergent aerating chambers 34', 35,which are similar to the chambers 34, 35 and include porous inner walls341:, 35a supplied with air through pipes 36' having valves 37. Thechambers of each pair are convergent and their lower walls are formed toprovide an outlet 38' closed by a door 38'a. A rod 60 lies in the troughbetween the two chambers 35' and it is supported at its upper end in abushing 61 extending through an opening in the wall 25' of the hood andat its lower end by a bracket 62 attached to the walls of chambers 35. Asuitable vibrating device 63 is attached to the upper end of the rod andthe agitation of the rod imparts movement to the heavy substances lyingnear it, so that they flow downwardly by gravity and do not collect inthe trough formed by chambers 35' and prevent the free movement of thecoarse material down the surfaces of the chambers to the outlet 38'.

A simple form of the separating apparatus is illustrated in Fig. 8 ascomprising a tank 64, which may be oblong in cross-section and is closedat the top by a cover 65, through which an inlet pipe 66 for admissionof the material mixture extends. The bottom of the tank is formed by apair of aerating chambers 67, 68 and the top of chamber 67 lies at ahigher level than the top of chamber 68, so that the lower end ofchamber 68 may terminate beneath and substantially in alignment with thelower end of chamber 67. At their lower ends, the

l walls of the chambers are extended to define an outlet side of thepartition 39. This material is made up mainly of finely divided aluminumoxide, which is rendered fluent by the air difiused into the chamberthrough the porous inner walls of the aerating chambers 34, 35, but thematerial may also contain pieces of the kiln lining and other foreignsubstances and lumps. The volumeand pressure of the air diffused intothe chamber 34, 35 is such that while it will render the alumina fluent,it will not maintain the undesired and less-readily suspendible foreignsubstances and lumps in suspension. Therefore,

such undesired components settle through the fluidized material andenter the outlet 38 at the bottom of chamber 33 above the door 38a,while the fluidized fine material rises in the chamber 33 at the side ofpartition 39 leading to the opening 40 and enters the cooler 41 throughthe opening. Within the cooler, the material is maintained compartment69 normally closed by a swinging door 70; The chambers 67, 68 aresubdivided by transverse partitions 71 into compartments, to which airis supplied through separate air pipes 72 having valves 73. A partition'74 extends downwardly from the cover in the transverse median plane ofthe tank 64 to terminate above the aerating chambers and the partitionhas an opening 74a through it. The wall of the tank 64 at the side ofpartition 74 remote from the inlet 66 has a material outlet 75 and anair outlet 76 leads from the top of the tank at the same side ofpartition 74 as the outlet 75. A deflector 77 mounted on a bracket 78 attached to the wall of the tank lies beneath the lower end of inlet 66. 4

In the operation of the separating apparatus of Fig. 8 for theseparation of undesired components in the form of lumps and foreignbodies from a finely divided ma-i terial,'the material mixture is fedinto the. tank through the inlet and the finely divided material isfluidized by air, which is diffused through the porous upper walls ofthe aerating chambers. 67, 68. The air rising through the material onopposite sides of partition 74 escapes asoline In order to effectthe'separation of the oversize components, the air valves 73 are soadjusted that the air supplied to the highest compartments of theaerating chambers enters the material mixture from those cornp r en at ae oci y sl h y e s h n th mi im m a e, whi h wouldmai ain the un es re cmpon nts in suspension. The valves 73Qthrough which air is supplied tothe lowest compartments of the-chambers, are

' o adju d t at t ve oc ty f the r e t ng he mate al f m h e chamber isght y in xeess of the m nhnmn va ue for ma nta n g'the fi y v ed m er an fluent cond on he air ss ng o.m the inte diate ompa tm nts is con ro dy t v s, so that its velocity is between the velocities of'the airiswine r m th he n low c m r m n B cause at he ih in t en of. a ratin habe s. he ad of flu d ze mater al bo th epm tt' mparts. of e chambers oers ebns derahly e re s a e to air flow than the head above thecompartments at the lower ends of the chambers. Because of this and ofthe adjustment of the air supply to the'cornpa'rtrnents as described,the velocity'of the air entering the material from the chambers variesin a direction down the tops of the chambers fairly uniformly fromslightly belowf tlierninimum value, which would prevent the undesiredcomponents from sinking through th"fiuidized material to slightly abovethe minimum value required forrnaintainin the fine material fluent. Theundesired components, accordingly; sink slowly through the fluidizedmaterial and enter the outlet 67, from which they can be periodicallyremoved by opening the door 70.

In the modified form of the separating apparatus shown in Fig. 10, thetank 79 has a material inlet 80 leading into a laterally offsetcompartment 81 defined in part by a partition 82, which extendsdownwardly from the top 83 of the tank and terminates below the normallevel of the material in the tank. The partition leaves the bottom ofcompartment 81 open to the interior of the tank, so that the materialentering the compartment may pass through it and into the tank. Inaddition to partition 82, the tank includes partitions 84, 85 extendingdownward from the top of the tank and having air openings 84a, 85a,respectively, near their upper ends. An air outlet 86 leads from the topof the tank between partitions 84, 85 and a partition 87 is mountedbetween partitions 84, 85 and lies wholly submerged in the materialwithin the tank during operation. A material outlet 88 is provided inthe wall of the tank remote from the chamber 81.

At its bottom, the tank is provided with inner porous walls 89, whichare convergent downwardly and lie at different heights. Outwardly fromeach of the porous walls, the tank has a solid wall 90 and the solid andporous walls of each pair form an air chamber 91, to which air issupplied through pipes 92. At the lower ends of the chambers, the walls90 are extended to form an outlet 93 containing a rotary gate valve 93a.

The air chambers 91 are not divided into compart ments, as in theconstruction of Fig. 8, but the desired variation in the velocity of theair entering the material is obtained by varying the resistance to theflow of air through the porous walls. For this purpose, the walls may bemade, as shown, in transverse sections decreasing in thickness in adirection down the walls. The thickest sections of the walls at theupper ends of the air chambers do not wholly correct for the resistanceto flow offered by the reduced head of material above these sections andslightly more air is likely to pass through the .;6 thickest sectionsof. the porous walls at th pp r ends thereof than thrpiugh the thinnersections farther down the walls. However, the thickness or the.wallsqand' the pressure of the air supplied to the air chambers aresuch that the air entering "the material thr ugh the top sections of:the walls has a vel city slightly less than the minimum yalue,whichiwould maintain the undesired cornponents .in'suspensio'n. The'velocity of the'a-iir entering the material decreases in a directiondown he walls and the velocity of the air entering the material hroug hethinnest sections of the walls is' above the mini um val e required formaintai ng the fine material fluentinstead f forming the porous walls 18w h'seetions of different thickness, the desire res t may he btained bymaking the .Walls of ceramic mat rial of niform thickness but varying inporosity;

'In the operation of the appar tus shown n Big! 0.

the material mixture entering the tank through inlet '80 falls HPQ theporous Qwjall .89heloyg the inlet and the finely divided constituent isfluidized, while the'undesired components settle through the. fluidizedmaterial. As the operation proceeds, the tank becomes'fil d' wi hfluidized material, whicli'trayels beneath partition 84, above and b w?Pfi i 0 nd beneath parti ion on the w y to the material. outlet 88.Theundesired components sink through the fluidizedrnaterialandentertheoutlet 93, from which they are discharged through the valve 93 whilethe" air escapes through the air outlet 86,.

The form of separating apparatus shown in Fig. 11 is closely similarto'that shown in Big. 10, except'that the material inlet 9.4. extendsdirectly into the tank 95 through its" top 96 and'terminatejs elow thelevel of the material outlet '97. The tank contains partitions 84, 85',and 87' similar in construction andfunction to the partitions 84, 85,,and, 87, respectively, of the Fig; 10 construction. The tank 9.5 hasasingle porous wall 98, which is inclined. downwardly and, with anonter'solid wall 99, forms an air chamber 100 supplied with air througha pipe 101. The air chamber 100 terminates close to the wall of the tankcontaining outlet 97 and, at the lower end of the air chamber, there isan outlet 102 from the tank leading to a screw conveyor 103 containing ashaft 104 and having an outlet 105. In the operation of the apparatus,the shaft is preferably driven continuously at a slow rate. The wall 98of air chamber 100 is of decreasingthickness or 'of increasing porosityin a direction down the wall in order to vary the velocity of the airentering the material for the purposes previously explained. In order toprevent escape of air through inlet 94, a deflector 106 is mountedwithin the tank below the inlet.

The apparatus shown in Fig. 12 is made up of four identical tanks 1 07disposed in a row. The first tank 107a has an inlet 108 for material andcontains an air deflector 109 below the lower end of the inlet. A pairof partitions 110, 111 are mounted below the top of the tank andterminate within the material at a distance above the inner porousinclined bottom wall 112 of the tank. The tank has an outer imperviouswall 113, which cooperates with wall 112 to form an air chamber 114supplied with air through a pipe 115. The wall 112 is of decreasingthickness or of increasing porosity in a direction down the wall. At thelower end of the wall, the'tank is provided with an outlet 116containing a rotary gate valve 117, and the tank has an air outlet 118above the outlet 116. The wall 119, which is common to tank 107a andtank 107b next to it, has an opening 119a for passage of material. Tank107b and the remaining tanks 107a and 107d are similar to tank 107a andthe fluidized material issues from tank 107d through an opening 120a inthe end wall 120 of the tank.

In order to show the effectiveness of the separation produced by the useof the invention, the results obtained by means of the apparatus shownin Fig. 8 but with inclined walls of varying thickness, as shown in Fig.10,

are given. The material mixture supplied to the apparatus contained10,000 parts by weight of aluminum oxide and 400 parts of crushed brick.The particle size of the aluminum oxide was such that 99.5% could passthrough a screen with openings of 0.037 mm., while all the brick piecescould pass through a screen with a mesh width of 4.76 mm. but wereretained on a screen with a mesh width of 2 mm. The material was treatedin the apparatus in the usual way and screen analyses were made of thematerial, which passed through the apparatus, and of the material, whichcollected at the bottom of the tank. It was found that 10 kg. of thematerial, which passed through the apparatus, contained only 2.5 g. ofmaterial unable to pass a screen with a mesh width of 2 mm. and theremaining coarse material collected in the material outlet. Theapparatus thus removed approximately 99.4% of the undesired componentsinthe mixture having a particle size greater than 2 mm. Such aseparation is regarded as highly satisfactory.

-We claim:

I 1. An apparatus for separating undesired components in the form offoreign substances and lumps from a mixture of the components and afinely divided material, which comprises a chamber having a bottomincluding an air-permeable section inclined upwardly toward a wall ofthe chamber, the chamber having an inlet and an outlet for solids at adistance above. the bottom, an outlet for the components adjacent thelower end of the inclined bottom section, means for introducing airthrough the inclined bottom section to aerate the mixture within thechamber, vertical partition means within the chamber above its bottom,and means for agitating the contents of the chamber extending along saidinclined section and reciprocable lengthwise.

2. A method of separating undesirable components in the form ofless-readily suspendible foreign substances and lumps from a mixture ofsuch components and a finely-divided, more readily suspendible materialwhich comprises introducing the mixture into an upper portion of a spaceat one side thereof, causing the entire mixture to flow downwardly atsaid side of the space in a confined zone which terminates a distanceabove the bottom of said space, introducing gas into said space at alevel below the bottom of said confined zone and over an area extendingto the side of said space opposite that into which the mixture wasintroduced, the gas being introduced in such volume and at such pressureas to' render fluent the finely-divided, more-readily suspendiblematerial, but in volume and at pressure insufficient to maintain theundesired and less-readily suspendible foreign substances and lumps insuspension, whereby such undesirable foreign substances andlumps areseparated from the finely-divided, more-readily suspendible material andsettle to the bottom of said space, while the finely-dividedmore-readily suspendible material flowing from the bottom of saidconfined zone rises through said opposite side of the space, anddischarging said finely-divided, morereadily suspendible material froman upper portion of said opposite side of the space.

3. The method of claim 2 which further includes subjecting to mechanicalagitation undesired and lessreadily suspendible foreign substances andlumps separated from the more-readily suspendible material.

References Cited in the file of this patent Morrow Nov. 6, 1956

